Hamilton was un­der a se­vere thun­der­storm watch for much of the day Thurs­day, with heavy rain fall­ing un­evenly across the city. The watch ended shortly af­ter 3:30 p.m.

En­vi­ron­ment Canada me­te­o­rol­o­gist Ge­off Coul­son said that by noon 13 mil­lime­tres of rain was mea­sured near John C. Munro Hamilton In­ter­na­tional Air­port, while 22.4 mm was mea­sured near the Royal Botan­i­cal Gar­dens.

Am­a­teur mea­sure­ments taken at other nearby spots and posted on­line show up­wards of 50 mm, he added, not­ing that a range of rain­fall amounts is typ­i­cal.

City spokesper­son Jas­mine Gra­ham said the brief del­uge spurred vis­i­ble “sur­charg­ing” — ba­si­cally wa­ter spewed up in the air — from a hand­ful of street drains, and around six res­i­dents re­ported base­ment sewer back­ups.

The sewage treat­ment plant on Wood­ward Av­enue also briefly had to al­low par­tially treated sewage to flow di­rectly into Red Hill Creek to avoid wide­spread sewer back­ups from ex­tra wa­ter in the sew­ers.

A catch basin blocked by trash and de­bris also con­trib­uted to flood­ing un­der the Birch Av­enue rail bridge. A ve­hi­cle stalled while try­ing to drive through the flooded un­der­pass and be­came stuck.

Gra­ham said no sim­i­lar prob­lems cropped up on city streets. Hamilton has spent mil­lions of dol­lars re­build­ing pre­vi­ously flood­prone un­der­passes at the Cen­ten­nial rail bridge and an­other on Ke­nil­worth Av­enue.

The City of Hamilton also closed all city sports fields and di­a­monds (ex­cept Her­itage Green No. 4) be­cause of the weather.

As of noon Thurs­day, Hamilton has had 88.4 mm of rain this month, on track to reach the July long-term av­er­age of 100.7 mm, Coul­son said.

JOHN RENNISON, THE HAMILTON SPEC­TA­TOR

A tow-truck driver tries to keep dry as he helps the owner of a ve­hi­cle that got stuck on Birch Av­enue Thurs­day.